Backside brush for cleaning wafer and cleaning apparatus having the same

Abstract

The present disclosure provides a backside brush for cleaning a backside of a wafer. The backside of the wafer has a central region and a periphery region surrounding the central region. The backside brush includes a backside brush core and a backside brush pad covering an outer surface of the backside brush core. The backside brush pad includes a soft pad and an abrasive pad. The soft pad of the backside brush pad covers a portion of the outer surface the backside brush core and is configured to brush the central region of the backside of the wafer. The abrasive pad of the backside brush pad covers another portion of the outer surface of the backside brush core and is configured to brush the periphery region of the backside of the wafer.

What is claimed is: 
     
         1 . A backside brush for cleaning a backside of a wafer, wherein the backside of the wafer has a central region and a periphery region surrounding the central region, the backside brush comprising:
 a backside brush core; and   a backside brush pad covering an outer surface of the backside brush core for brushing the backside of the wafer, the backside brush pad comprising:
 a soft pad covering a portion of the outer surface the backside brush core and configured to brush the central region of the backside of the wafer; and 
 an abrasive pad covering another portion of the outer surface of the backside brush core and configured to brush the periphery region of the backside of the wafer. 
   
     
     
         2 . The backside brush of  claim 1 , wherein the soft pad of the backside brush pad is made of polyvinyl alcohol (PVA). 
     
     
         3 . The backside brush of  claim 1 , wherein the abrasive pad of the backside brush pad includes at least one of sand papers, polyurethane, non-woven fabrics, and asbestos. 
     
     
         4 . The backside brush of  claim 1 , wherein a hardness of the soft pad of the backside brush pad is lower than a hardness of the abrasive pad of the backside brush pad. 
     
     
         5 . The backside brush of  claim 1 , wherein the soft pad of the backside brush pad comprises a plurality of soft protrusions configured to make contact with the central region of the backside of the wafer. 
     
     
         6 . The backside brush of  claim 1 , wherein the abrasive pad of the backside brush pad comprises a plurality of abrasive protrusions configured to make contact with the periphery region of the backside of the wafer. 
     
     
         7 . The backside brush of  claim 1 , wherein the backside brush core has a shape of a cylindrical rod, and the abrasive pad of the backside brush is disposed at one end of the backside brush core. 
     
     
         8 . The backside brush of  claim 1 , wherein the backside brush core has a shape of a cylindrical rod, and the abrasive pad of the backside brush has two portions respectively disposed at two ends of the backside brush core. 
     
     
         9 . A cleaning apparatus for cleaning a wafer, the cleaning apparatus comprising:
 a frontside brush for cleaning a frontside of the wafer, the frontside brush comprising a frontside brush core and a frontside brush pad covering an outer surface of the frontside brush core; and   a backside brush for cleaning a backside of the wafer, wherein the backside of the wafer has a central region and a periphery region surrounding the central region, and the backside brush comprising:
 a backside brush core; and 
 a backside brush pad covering an outer surface of the backside brush core for brushing the backside of the wafer, the backside brush pad comprising:
 a soft pad covering a portion of the outer surface of the backside brush core, wherein the soft pad is configured to brush the central region of the backside of the wafer; and 
 an abrasive pad covering another portion of the outer surface of the backside brush core, wherein the abrasive pad is configured to brush the periphery region of the backside of the wafer. 
 
   
     
     
         10 . The cleaning apparatus of  claim 9 , wherein the frontside brush pad is made of polyvinyl alcohol (PVA), and comprises a plurality of protrusions configured to make contact with the frontside of the wafer. 
     
     
         11 . The cleaning apparatus of  claim 9 , wherein the soft pad of the backside brush pad is made of polyvinyl alcohol (PVA), and comprises a plurality of soft protrusions configured to be in contact with the central region of the backside of the wafer. 
     
     
         12 . The cleaning apparatus of  claim 9 , wherein the abrasive pad of the backside brush pad comprises a plurality of abrasive protrusions configured to be in contact with the periphery region of the backside of the wafer, and includes at least one of sand papers, polyurethane, non-woven fabrics, and asbestos. 
     
     
         13 . The cleaning apparatus of  claim 9 , wherein a hardness of the soft pad of the backside brush pad is lower than a hardness of the abrasive pad of the backside brush pad. 
     
     
         14 . The cleaning apparatus of  claim 9 , wherein the backside brush core has a shape of a cylindrical rod, and the abrasive pad of the backside brush pad is disposed at one end of the backside brush core. 
     
     
         15 . The cleaning apparatus of  claim 9 , wherein the backside brush core has a shape of a cylindrical rod, and the abrasive pad of the backside brush pad has two portions respectively disposed at two ends of the backside brush core. 
     
     
         16 . The cleaning apparatus of  claim 9 , further comprising a brush motor coupled to the frontside brush and the backside brush to rotate the frontside brush and the backside brush. 
     
     
         17 . The cleaning apparatus of  claim 9 , further comprising at least one roller configured to make contact with an outer edge of the wafer and rotate the wafer. 
     
     
         18 . The cleaning apparatus of  claim 9 , further comprising a water spray unit configured to supply deionized water to the wafer. 
     
     
         19 . A method of cleaning a wafer, comprising:
 loading the wafer between a frontside brush and a backside brush of a cleaning apparatus;   brushing a frontside of the wafer by the frontside brush of the cleaning apparatus;   brushing a backside of the wafer by the backside brush of the cleaning apparatus, wherein a periphery region of the backside of the wafer is brushed by an abrasive pad of the backside brush, and a central region of the backside of the wafer is brushed by a soft pad of the backside brush; and   providing deionized water by a water spray unit of the cleaning apparatus to the frontside and the backside of the wafer to clean the wafer.   
     
     
         20 . The method of  claim 19 , wherein a hardness of the soft pad of the backside brush pad is lower than a hardness of the abrasive pad of the backside brush pad.